1. Field of the Invention
The present invention relates to a lens barrel that has a diaphragm blade and changes a diaphragm aperture in connection with a zoom operation, and an image pickup apparatus like a digital camera provided with the lens barrel.
2. Description of the Related Art
A conventional image pickup apparatus (a digital camera, etc.) has a lens barrel that is provided with an exclusive actuator and a member linked to diaphragm blades as a driving mechanism for the diaphragm blades, and that changes a diaphragm aperture by operating the actuator to open and close the diaphragm blades.
However, when the actuator only for the diaphragm blades is provided, a space for mounting the actuator is necessary around the blades in the lens barrel, which enlarges a size of not only the lens barrel but also a camera, and increases a cost.
Japanese Laid-Open Patent Publication (Kokai) No. H9-211534 (JP H9-211534A) discloses a technique that a cam part (a grooved cam etc.) is provided in a lens barrel that moves in an optical axis direction so that a movement of the lens barrel in the optical axis direction operates a lever member through the cam part and the lever member drives the diaphragm blades linked with the lever member.
Although the technique of the JP H9-211534A does not need the actuator only for the diaphragm blades, a variation in a part accuracy may cause backlash between the lever member and the cam part and between the diaphragm blades and the lever member, which possibly changes the diaphragm aperture.